The present invention is directed to a method for handling telecommunications connections via a public exchange having terminal devices that are used by a number of telecommunications subscribers, whereby the allocation of a telecommunications subscriber to such a telecommunications connection ensues in the terminal devices.
In such a situation, the switching network mainly serves as a transport medium and has no information about the subscribers that the connections running over it are related to and what functions are handled in this context.
An example of such a constellation is the connection of a mailbox system, which—as seen from the point of view of the exchange—is a terminal device that can be reached under a specific telephone number but that is available to a number of subscribers. When a telephone subscriber wishes to query the content of his individual mailbox memory, then he must set up a telephone connection to the mailbox system via the public exchange and is then prompted, for example, to send an identification code to the mailbox system via the existing voice connection, this giving him access to his voice memory part thereat. Low information about the voice memory part that is being queried is present in the exchange in this context.
In this, as in comparable cases, functions implemented in the public exchange can not be applied to telephone subscribers that share a terminal device. One example of such a function is the possibility of monitoring telephone connections that, for example, is required by the German communications law and that also relates to voice or fax mailboxes.
Up to now, one therefore had to proceed such that the function relating to the possibility of monitoring was additionally implemented in the terminal device for terminal devices like the mailbox system or, such terminal devices were expanded by additional connection possibilities.
European Patent Application No. 0,512,704 discloses a system and a method for recognizing the point of origin of emergency calls in an emergency call system. What is thereby particularly involved is the identification of one of several stations of a private network from which an emergency call is supplied into a public network. In the proposed system, means are provided for a protocol transformation of the protocol of the private network into a protocol that can be interpreted by the emergency call network, and means are provided for allocating a telephone number to the station initiating the emergency call, and, finally, means are provided for the transmission of this number to central response location of the emergency call system. The solution is expressly tailored to a specific emergency call system and therefore relates only to very specific connections of the private network to the public network. For realizing the specific functions, specific components that are not allocated to the general telecommunication network are also provided in the emergency call system, for instance what is referred to as a station translation system (STS) module, a central organization (CO), and a switching tandem. The data traffic on the part of the private network required for the terminal station identification sequences with these specific components of the emergency call system and is only activated in the case of an emergency call.